One embodiment of such a hinge pin device is illustrated in French Published Patent Application No. 2596711, in which the hinge pin section is substantially semi-cylindrical with a flat face turned towards the interior of the windscreen wiper arm, and in which the bearing section comprises an insertion recess which has an internal section with semi-cylindrical contours and a diameter substantially equal to that of the section of the hinge pin, and a section open towards the exterior delimited by flat faces which are separated by a distance less than the diameter of the section of the hinge pin and slightly greater than the dimension thereof measured perpendicular to the flat face, the section of the hinge pin being mounted in the interior section of the recess.
Such a design is advantageous in that it enables the two components to be produced economically by moulding from plastic material, but it is not entirely satisfactory from the operational point of view insofar as there is a substantial risk of the section of the hinge pin escaping from its recess.